Abstract

Screening test such as fecal occult blood test (FOBT) and fecal immunochemical tests (FIT) in the asymptomatic population proved to be successful in reducing incidence and mortality rate in colorectal cancer (CRC) patients. The relative high false positive rates, mediocre cost-effectiveness, and poor patient uptake remain some of the challenges for using FOBT or FIT for early CRC detection. This paper describes the use of surface-enhanced Raman spectroscopy (SERS) on blood plasma as an alternative screening method to the traditional CRC screening approaches. Blood plasma samples were collected from 21 CRC patients and 25 healthy controls. Silver nanoparticles were prepared as SERS substrate and mixed thoroughly with plasma samples before Raman spectral measurement. Spectra were analyzed with principal component analysis (PCA) combined with linear discriminant analysis (LDA). Raman spectra for cancerous group and normal group could be readily separated in the score plots. A diagnostic sensitivity and specificity of 71.4% and 84.0% were obtained. Our test results showed that SERS blood plasma test could be a potential CRC screening test to detect early CRC.

© 2015 Optical Society of America